//**********************************************************************************
//GMCMid2Prob4.java
//
//Name: Gabriel Martins	de	Castro
//Class:	COMSC	110L.51
//Date: /2014
//Instructor: Dr.	Chunyan Bai
//
//Purpose: 
//***********************************************************************************

import java.util.Scanner;

public class GMCMid2Prob4
{
      public static void main (String[] args)
   {
   
      boolean loop = false;
      int num = 0;
      
      while(!loop)
      {
         System.out.println("Enter a number : ");
         Scanner input = new Scanner(System.in);
         num = input.nextInt();
         
         if(num < 2)
            System.out.println("Error! Number cannot be less than 2!");
         else
            loop = true;
         
      }
      
      int sum = 0;      
      for(int i = 2; i <= num; i+=2)
         sum+=i;
      
      System.out.print(sum + " = 2");
      
      for(int i = 4; i <= num; i+=2)
         System.out.print("+" + i);
      
   }
}
